Electric lamp for beacon lights



Mana 13, i980. E. HURWHZ ELECTRIC LAMP FOR BEACON LIGHTS Filed April 27, 1929 www: HHHHHIIUIMII by Mf/W Patented Mar. 18, 1930 UNITED STATES PATENT OFFICE EUGEN HURWITZ, OF BERLIN, GERMANY, ASSIGNOR T GENERAL ELECTRIC COMPANY A CORPORATION OF NEW YORK ELECTRIC LAMP FOR BEACON LIGHTS Application led April 27, 1929, Serial No. 358,668, and in Germany May 1, 1928.

High-power incandescent lamps have been used as light sources for beacons and light houses because such lamps are Very easily operated. However, the light from such an incandescent lamp must not start from a concentrated or a semi-concentrated light source, since otherwise the ridges of the system of lenses (mostly F resnel lenses) would cause undesirably wide and extensive shadows and would thus considerably affect the light distribution. For this reason, lamps for this service have been provided with a bee-hive shaped light radiator consisting of several wires braided together, but the distribution of the light emitted by such lamps was not entirely satisfactory, since the luminous circumfercntial surface of the light radiator did not have everywhere the same luminous intensity because of the dark meshes between the bright wires.

The object of this inventionis to provide in the interior of an electric lamp, a large luminous surface of even and high luminous intensity. To this end, a diffusing screen such as a ground glass, or opal glass, translucent quartz, or porcelain, is mounted inside of the lamp to surround the high-power light source very closely. Inasmuch as the light source itself is made invisible, owing to the ditl'using screen which acts as alight radiator, the light source may be of any shape and may even be concentrated. lt may consist ottone or of several helically-wound laments which are crowded into a narrow space, or it may consist of a hemispherical or spherical tungsten electrode to which an arc discharge takes place.

In the accompanying drawing which shows some of the several forms of electric lamps embodying and made according to the invention, igure l is a longitudinal section of an incandescent lamp with a cylindrical di'user; Figure 2 an elevation of a lamp mount provided with a cup-shaped diuser; and Figure 3 is alongitudinal section of a tungsten arc lamp with a bowl diuser.

Figure l shows an incandescent lamp which comprises a spherical glass bulba, preferably lled with an inert gas and having a` stem b which carries the current leads a and d, the

arbor e, the-inner leads f, and the coiled lilament g. Supports z' secured or clamped to the stem preferably by clamps h hold a translucent diffusing screen lc, which closely surrounds the filament g. The screen may consist of any kind of di'using material, such as ground glass, opal glass, translucent quartz glass, or porcelain.

The incandescent lamp shown in Figure 2 is in general of the same design, but has two coiled filaments g1 and g2 which are surrounded by a cup-shaped screen lo, of light diusing material. The supports i for the screen 7c, are embedded at their upper ends in the. stem b of the lamp.

Figure 3 shows a tungsten arc lamp comprising a spherical bulb a, lilled with inert gas and having a stem b, with the sealed-in leads or conductors c and d. An arc is Jformed between a spherical anode Z and a hemispherical cathode m, which, in the idle position, lies against the anode; the support rod a which carries this cathode is formed in part of a bimetallic strip o, which withdraws 'the cathode m from the anode Z, whenever current is applied, thereby starting the arc. The two electrodes Z, m, of the lamp are surrounded in this case by a cup-shaped screen 7a2, which consists of light-diffusing material.

rlhe new lamps with the enclosed-light-difusing screen are not only suitable for beacons but can be used anywhere to advantage where a large luminous surface is desired with an even luminous flux.

1What l claim as new and desire to secure by Letters Patent of the United States, is:

l. An electric lamp comprising a sealed bulb, a light source in said bulb, and a translucent screen mounted in said bulb to partially enclose said light source.

2. An electric lamp comprising a sealed bulb, a stem extending into said bulb, a light source on said stem, and a translucent screen mounted on said stem to intercept the light from said source.

3. An electric lamp comprising a sealed bulb, a stem extending into said bulb, a mass of metal mounted on said stem to translate electrical energy into light, and a translucent screen mounted in said bulb adjacent said mass of metal to intercept the light from said metal.

4. An electric lamp comprising a sealed bulb, a filament in said bulb, means for supplying current to said lalnent to render it i11- candescent, and a translucent screen substantially enclosing said filament to difuse the li ht and become an extended light source of su stantially uniform brilliancy.

5. An electric lamp comprising a, sealed bulb containing an inert gas, an electrode in said bulb through which current iows to produce light at a predetermined point in said bulb, and a translucent screen mounted in said bulb adjacent said point to intercept the light fromsaid point and thereby become an extended light source of substantially uniform brilliancy 6. An electric lamp comprisino' a sealed bulb containingan inert gas, an electrode in said bulb through which current iows to produce light at a predetermined point in said bulb, and a screen of translucent vitreous material mounted in said bulb to substantially enc-lose lsaid electrode.

In Witness whereof Ivhave hereunto set my hand this 16th day of A ril, 1929.

EN HURWTZ. 

